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PN401FXTH
161-051300-001FEBRUARY, 2008
4and
Installation, Operation
RENEWAL PARTS IDENTIFICATION
Chromalox®
Chromalox Type FXTH Flexible Tank Heater
Amp / Tube Catalog Number of RecommendedMinimum Heater Heater No. Tubes Approx OCC or WCC Control CentersManhole Length Width and Catalog Net Wt.
kW 240 480 Size (In.) B C Circuits Number* Lbs. 240V 480V
*Suffix letters with FXTH Catalog Number indicate modification from standard as follows:V= Voltage, W= Wattage, A= change in riser length, R= low temperature alarm contactor, D= temperature indicator and XX = special.
Thermowell
3/4” NPT
Thermowell
Riser
Three TubeHeater Assembly
Two TubeHeater Assembly
Single TubeHeater Assembly
HeaterTerminalHousing
2-1/2” NPT 6-1/4”2”
Vent Tube
Notes:1. Min. fluid Depth for safe heater operation is 12”.2. 5/8” - 11 x 1 in. long hex head bolts. 8 required.
The Chromalox FXTH Flexible Tank Heater is designed for heat-ing viscous liquids in large steel, concrete or fibrous glass tanks withnormal manhole entry. Standard equipment with every heaterincludes flexible pipe and 14’ riser(s), two lifting cables, 4” highsludge legs and a 50-250° non-indicating thermostat with well,overtemperature probe and weatherproof terminal housing.
The Control Center OCC (NEMA XII, oil and dust-tight con-struction) or WCC (NEMA IV, weather-resistant construction) isdesigned for controlling the temperature of the viscous liquids by reg-ulating the FXTH's on-off cycle. It is mounted remotely with standardcomponents consisting of a NEMA XII or NEMA IV enclosure with
vertical wall mounted brackets and hasp and staple for padlocking.Electrical components include: Failsafe overheat device, master cir-cuit-breaker, contactor(s), relay(s), selector switch, pilot lights, fusesand a 120-volt control circuit transformer.
IMPORTANT-Before attempting to uncrate or install the FXTHheater, read and understand all of the following instructions. Properhandling is absolutely necessary to obtain satisfactory operation. Allelectrical connections are to be made by a qualified electrician. Toavoid excessive separation, stratification, sludge formation, etc., inyour FXTH heated storage tank, consult a qualified oil supplierregarding selection and blending of fuel oils.
Heater Front End
Front Lifting Cable
OvertemperatureProbes
Rear Lifting CableHeater
Back End
FlexibleRisers
Terminal HousingRiser UnionsSludge Leg Base Plates
1. MechanicalThe heater assembly has undergone a rigorous leak test just priorto shipment from the factory. Visually inspect all joints and flextube surfaces to insure no mechanical damage has incurred duringshipping. Contact carrier if heater shows signs of damage. Do notattempt to install heater if damage is evident. Do not attempt totighten or remove any of the threaded fittings in the flexible tubeassembly. If the sealing performed at the factory has been broken.the unit must undergo another complete leak test supervised by anAuthorized Chromalox Serviceman before installing in tank.
2. ElectricalA. Open control unit cover and examine electrical components
for any damage which may have been incurred during ship-ment. Contact carrier and report any damage noted.
B. CAUTION: Retighten all electrical connections and mountedcomponents which may have loosened during shipment.
PRE·INSTALLATION CHECK OF HEATER
NOTE: Inspect shipping crates before opening. Contact the carrier ifdamage is evident.
1. Check to see that all components are included. FXTH immersionheaters are shipped as subassemblies consisting of (a) flexibleheater with riser tubes, (b) terminal housing, (c) thermowells andvent tube, and (d) control unit (if ordered).
2. To unpack flexible heater, keep crate in upright and horizontalposition when removing heater. Only top boards of crate need tobe removed.
3. When lifting heater assembly, do not bend heater to radius lessthan 22". Heaters should be flexed in vertical plane only. This isa plane perpendicular to the sludge leg base plates. Bending inhorizontal plane can damage internal ceramic insulators.
4. Use several people to lift heater - the number depends on thelength and weight of the heater. As a guide, four men should beused to lift and handle a dual tube 20 ft. unit.
5. Do not put any stress on the flexible riser tubes. These are notdesigned for supporting weight. The unit must be lifted by eitherthe 3" heater tubes or the steel lifting cables furnished with heaterand located at both ends of heater. See Figure A.
6. Set heater in upright position on flat surface. Avoid any lateralbending.
CAUTION: Never drop heater or subject it to mechanical shock.
Machining of Manhole Cover to ReceiveFXTH Immersion Heater Terminal Box
1. Surface on top side of Tank Cover must be suitable for good gasket seating. The 13"dia. area containing the gasket seat must be free of loose scale and rust and shall havea maximum surface roughness of 250 RMS.
2. Bolt hole orientation to axis of storage tank is not important.
Machining of Manhole Cover to ReceiveFXTH Immersion Heater Adapter Assembly
1. This Dimension is for Storage Tank Clearance Hole.
1. Double check internal dimensions of tank to be sure heater legswill stand straight on portion of tank bottom to its full lengthwhen in its operating position.
2. Remove any obstructions which may interfere with proper instal-lation of heater into tank.
3. Clean manhole area to eliminate dirt and water which can bepicked up by heater during its insertion into tank.
4. Time the installation so oil level in tank is half full or less. Thiswill greatly facilitate insertion and positioning of heater.
5. Check sludge in bottom of tank to ensure it does not interfere withoperation of heater. Standard FXTH heaters are supplied with 4”sludge legs. Sludge in excess of 3” must be removed before
installing heater. Sludge must not touch the corrugated heatingsurface of the immersion unit.
6. Check point of tank suction to make sure it is 12” or more off bot-tom of tank. This will insure a minimum liquid level of 12” andprevent heater from being uncovered while in operation. Theheater must not be energized unless it is completely submerged.
7. Machine manhole cover per Figure B or install optional terminalhousing manhole adapter to manhole cover or storage tank perFigure C. All welds must be liquid tight.
DANGER: Hazard of Fire. If adapter is to be welded directly intotank, remove flammable liquids, and vent all combustible gases orvapors from storage tank before performing welding operations.
1. If tank is type with manhole located near end of tank rather thanin center, install a temporary pulling cable at far end of tankthrough any available port such as (l) fill pipe, (2) suction port, (3)auxiliary manhole, etc., and thread the cable through the tank andout the manhole to be used for installing the heater. The pullingcable will be used to pull front lifting cable through auxiliary portand then pulling cable is disconnected. See Figure D.
2. Align heater assembly along centerline of tank having rear end(riser end) of assembly farthest from manhole. Note: On tankswith manhole near end rather than in center heater assemblyshould be placed on side of manhole farthest from end of tank.See Figure E.
3. Tie the riser(s) with rope or suitable line at a point just below theunion on riser(s). Anchor rope to any convenient nearby anchor-ing point. Length of rope should be sufficient to allow riser(s) tobe inserted into tank just inside manhole but not below oil level.CAUTION: If oil gets into riser, it will cause failure of the heat-ing element.
4. Carefully turn heater over, feet upward, taking care it is flexed inonly the one plane. (See Figure F.) Support must be maintained onriser end of heater to avoid overstressing riser(s) until heater islowered into tank.
5. Begin lowering heater into tank as per Figure G, Step 1 thru 3(end manhole) or Figure H, Step 4 thru 7 (center manhole). Oncethe heater has touched bottom, use pulling wire (front liftingcable) to pull heater toward far end of tank.
6. Before lowering back end of heater, visually gage the remaininglength of heater to be laid down, to be certain an equal amount ofclearance is allowed at both ends of tank. Back end of heater islowered into place using rear lifting cable. CAUTION: NEVERUSE RISERS TO SUPPORT HEATER TUBES.
7. Where additional heater assemblies are to be installed in the samemanhole, follow same procedure, being careful not to interferewith risers or cable on the initial heater.
NOTE: In tanks where the configuration does not allow followingthe above procedure, or in above ground tanks, ask for Factory rec-ommendations for installation of heater.
Figure G – Tanks with Manholes Near End
Step 1
Step 2
Step 3
Figure H – Tanks with Center Manhole
Step 4
Step 5
Step 6
Step 7
INSTALLATION OF FXTH TERMINAL HOUSING
A. Position manhole cover adjacent to manhole. Very carefully untierope from anchoring point and pass it through (1) manhole gasket,(2) opening in manhole cover, and (3) terminal housing gasket.Securely refasten rope to anchoring point. Do not allow riserend(s) to fall into oil, or permanent damage will result to theheater. Bolt down manhole cover using a suitable gasket sealant ifrequired to obtain water-tight seal.
B. Pull riser(s) upward into position next to terminal housing. Wrapteflon tape on threaded riser connections and fasten into undersideof terminal housing. Unused connections on bottom of housingwill already contain flush plugs. Attach lifting cables to ring onunder side of terminal housing.
C. Bolt terminal housing to manhole cover or manhole coveradapter, again using suitable gasket cement. If manhole cover ismachined per Figure B, be sure to install copper gasket washersunder bolt heads. Position housing so conduit connections are inthe most convenient position for your particular installation.Connect all riser leads to terminals, following markers on wiresand terminals referring to wiring diagram Figure J.
D. Install power leads from terminal housing to control center. SeeSpecifications Table, Page I for amperages to determine wire andconduit size as determined by the National Electric Code.
E. To install thermostat wells, insert closed end of the well into brassfitting in bottom of terminal housing. Push well completely tobottom of tank. A preliminary measurement from manhole levelto tank bottom will aid proper insertion. The well may first hit theheater. It is then necessary to manipulate the well so that it willglance off the rounded heater surface and extend to tank bottom.Mark side of tube at the swage fitting and then pun upward sev-eral feet to working level. Using a tube cutter, cut the tube at apoint exactly 7” below the mark. Once the tube is cut, be extreme-ly careful the tube is not allowed to drop through fitting and intotank. Partially tighten fitting so this cannot happen. Position theupper end of well 5” off top of tube fitting, then firmly tighten thefitting. Insert bushing (located in shipping bag inside of terminalhousing) into top of well. This will prevent burrs on tube fromcutting the bulb or capillary of thermostat. Repeat this procedureuntil all wells are installed. There can be as many as three wells;(1) Thermostat, (2) Temperature Indicator, (3) Low Limit Alarm.
F. Install thermostat mounting plate. Make sure thermowells arealigned with openings in plate and over-temperature leads fromriser are brought through plate. Fasten plate into position.
4
INSTALLATION OF HEATER ASSEMBLY IN TANK (cont’d.)
G. Carefully unwind and straighten thermostat capillary tube. Thecapillary must be reasonably straight. Be absolutely certain thebulb is seated at bottom of well. Carefully coil any excess capil-lary and position next to thermostat and away from electrical con-nections. Repeat same procedure if low limit alarm is provided.Attach wire for overtemperature sensor to terminals.NOTE: Over-temperature control is located in the ChromaloxControl Center. If heater is supplied without control center, besure to obtain an over-temperature control for a positive thermis-tor, otherwise heater will be without over-temperature protection.
H. If the low temperature thermostat is being used, connect annunci-ator leads directly to terminals on this thermostat and provide anindependent power source. The switch rating is; 20 amp @ 115V,15 amp @ 230V, pilot duty 125VA.
I. If temperature indicator is employed, wire in accordance withFigure J. Use wire size as recommended for connecting to controlcenter.
J. Install control wiring through 3/4" conduit connection as indicat-ed on page 1. Leave lid off' terminal housing until operationalcheck is completed. Install breather tube on the outside of the ter-minal box as shown on page 1, Make sure top of tube is at least12" above the drainage water level. CAUTION: All conduit con-nections to terminal housing must be sealed to prevent entry ofany water, water vapor or condensation into terminal housing.Breather tube length may be cut to shorten height, or extended forhigher flood levels by using 3/8” compression tube coupling and3/8” tubing, as desired between formed breather tube and elbowfitting on side of terminal housing.
TemperatureIndicator (Optional)
Low Temp. AlarmContacts (Optional)
Non-IndicatingTemp. Control
4Overtemp.Probes
TerminalBlock
8765
8765
8765
4321
TerminalBlock
Overtemp.Control
1CR
1CR
2 TDR1 TDR
HeatHtr. Contactor #1
#1 Time Delay Relay(15 Sec.)
#2 Time Delay Relay(30 Sec.)
HeatHeater Contactor #2
HeatHeater Contactor #3
Overtemp.
Control Relay
Power OnX2 X1
GISS Off - On
Control
H4 H2 H3 H1
H4 H2 H3 H1 H4 H2H3 H1240V 480V
BL1
BL2BL3
CL1
CL2CL3
Ground
C3
C2
3
2
C11 AL1
AL2AL3
TerminalBlocks
FusesCircuitBreaker
L1L2L3 IL3
IL2IL1
1 TDR 2
32 TDR
1CRA1A2
Audible Alarm(Optional)
Thermistors located on heater with leads in conduit riser.One thremistor per heater tube.
1 Heater 3 Heaters2 Heaters
1. Contactor “1 CON” and no fuses are supplied on single stage models.2. Used on two stage models - fuses “3FU thru 8FU” - Contactor “2 Con” - Time delay relay “1TDR” - Pilot light “3LT”.3. Used on three stage models - fuses “3FU thru 11FU” - Contactor “2 Con & 3 Con” - Time delay relay “1TDR & 2TDR” - Pilot lights “3LT and 4LT”.4. Termistor connections: Necessary Jumpers - Factory Wired
NOTES:
F8
F3
F4F5
F6F7
C3
R
AC2
A
C1A
F2F1
F10
F11
F9OCC & WCC Control Center
5
Figure J
ELECTRICAL AND OPERATIONAL CHECKS
A. Having circuit breaker and power switch in “off” position, makesure proper voltage supplied matches voltage of control panel andelements.
B. Adjust controlling thermostat in terminal housing to a 50°F read-ing. Increase setting until thermostat switch just “clicks”. Thissetting is to be used for initial heater checkout.
C. Turn circuit breaker to “on” and note green power light comingon. Turn on power switch and note first amber light will come on,and then subsequent amber light(s) as explained in Section.
D. Observe control panel as heater goes through several heatingcycles. A cycle is determined when all amber lights are off. Cycleinterval can vary widely depending on amount of oil in tank.However, the thermostat has been set to keep the cycle time to aminimum.
E. Turn off circuit breaker and power switch, then re-set thermostatto desired setting for normal operation. The thermostat contains afactory adjusted stop which prevents settings above 150°F.
F. If low temperature alarm feature is provided, set this control 10°to 15°F below the control thermostat setting.
G. Installation of terminal housing lid and gasket (with proper gasketsealant) completes the check-out procedure.
H. If any difficulties are encountered during the installation andcheck-out, call your local Chromalox Representative orChromalox Product Service.
INSTALLATION OF REMOTE CONTROL CENTER
CAUTION: Hazard of electric shock. Any installation involvingelectric must be grounded to earth to eliminate shock hazard.1. A safe maximum temperature limit on control cabinet compo-
nents is 125°F. Choose a mounting location not in direct sunlightor exposed to any other source of excessive heat. If the panel mustbe mounted in direct sun, a sun shield must be employed.
2. Install proper control and power wiring to control center as perFigure J. Power lines are to be sized for the particular heater load.Double check to insure proper grounding procedures have beenfollowed for heaters and control panel.
3. Available inside control panel are connections A and A1 whichprovide for an over-temperature alarm; such as, horn, bell, etc., tobe mounted remotely as required. These terminals are rated at50VA, 120V.
4. ElectricalA. CAUTION: Hazard of severe shock. Make sure circuit
breaker and panel switch are in “off” position.B. Make knockouts in control cabinet which are desired for final
wiring installation.C. Connect leads from riser(s) to identified terminals shown on
Figure J.D. TEMPORARY WIRING TO SIMULATE ACTIVATION OF
CONTROL CIRCUIT.1. Jumper terminals S to S1.2. Connect overtemperature control leads to terminals 5, 6, 7
or 8 as shown on Figure J.3. Connect green ground wire lead from riser(s) to grounding
lug in control box and from control box to a suitableground.
4. Connect power cable of proper voltage to input of controlbox.
5. Secure control box door, then place circuit breaker in “on”position and energize heater with panel switch. Start with45 second time interval and increase until a definite rise intemperature on each heater tube can be felt with the barehand. NOTE: Adjustable time delay(s) in multi-stage unitshave been preset at factory to provide steps for energizingindividual circuits.
6. Observe green light (which indicates “power”) when clos-ing circuit breaker, first amber light with panel switch "on"and subsequent amber light(s) (if any) at approximately 15second intervals.
7. Have qualified electrician, using an amprobe, check amper-age in individual heater leads to insure uniform amperage.
8. Turn circuit breaker to “off” position and remove tempo-rary jumper from terminals Sand S1
Max. No. OCC WCC Inches Approx.Max. Amps Per of Dust and Oil Weatherproof Net Wt.kW Volts Circuit Circuits Tight Models Models H W D Lbs.
Specifications – OCC and WCC Control Center (All Phases)
6
OPTIONAL EQUIPMENT
Temperature Indicators (Suffix “D”)(FXTH Heater Assembly and Control Center will have
suffix "D" e.g. FXTH-11206D, WCG15-213D)
MOUNTINGTemperature indicators are balanced for accurate reading in a normalvertical position unless specified otherwise. All pyrometers labeled"shielded meter" may be used in any type of panel with little or noeffect on calibration. Those labeled "non-magnetic" must be usedonly on aluminum, plastic, wood or other non-magnetic panels. Theywill read low if mounted in a steel panel. Pyrometers which arelabeled "magnetic" are intended for installation on steel panels. Asteel compensating ring is normally supplied where panel material isnot specified. Discard the ring when mounting on a steel panel. If thepyrometer is used on a non-magnetic panel, the steel ring must beused. Be sure the slit in the ring is at the top of the meter barrel andthe ring is pushed as far forward as it will go.
THERMOCOUPLE SELECTION AND CALIBRATIONEach pyrometer is marked on the dial with the type of thermocoupleand the total external resistance for which it is calibrated. Use of anyother type of thermocouple or one with a higher resistance thanmarked will result in incorrect readings. (Type J thermocouples arenormally used.) All standard pyrometers are calibrated for 10 ohmsexternal thermocouple resistance and are provided with a 10 ohm cal-ibrating resistor bobbin. (Non-standard pyrometers are usually cali-brated for the specific external resistance ordered and no resistor bob-bin is supplied.) This resistor bobbin must be adjusted so the totalresistance of the thermocouple and the bobbin add up to 10 ohms inorder to maintain calibration accuracy. Therefore, for a 5 foot, 20gauge, iron-constantan thermocouple, the resistance of the thermo-couple would be approximately 1.75 ohms and this resistance must besubtracted from the calibrating bobbin. Each turn of the wire on theresistor bobbin represents 0.5 ohms and for this example, 3-1/2 turnswould be removed. The total resistance of the thermocouple plus theresistor bobbin would then add up to 10 ohms. For other values ofthermocouple resistance, simply remove more or less turns to adjustfor the total value of external resistance marked on the pyrometerdial.
It is very important the resistor wire be properly soldered afteradjusting.
NOTE: When Thermocouples with external resistance higher than 10ohms will be used, a special pyrometer will be required. The use ofother than thermocouple wire for leads or extensions may result inimproper ambient compensation.
ABBREVIATED TABLE OF THERMOCOUPLE RESISTANCEThe table lists the resistance in ohms per pair-foot for various typesof commonly used thermocouples for a number of different gauges ofwire. By using this table, it is necessary only to measure the length ofthe thermocouple, knowing the type and gauge, to determine itsapproximate resistance. (Actual measurement of the thermocoupleresistance is preferred to using the table.)
Ohms Per Pair - FootIron/Constantan Copper/Constantan Chromel/Alumel
Gauge B & S (Type J) (Type T) (Type K)
CHROMALOX TYPE TMC 7-DAY TIMER
TMC 7-day Calendar, Electric Dial Timer is used to provide auto-matic start-up/off-on control of large tank heaters or could be set upfor non-peak operation. Standard features: 7-day calendar dial per-mits different on/off schedules on different days of week. 2 to 14replaceable trippers for up to 4 on/off operations per day, up to 28on/off operations per week. 3 hour minimum on or off time; 21 hourmaximum on or off time. Independent 4-pole design allows SPST,DPST, SPDT, switching. Manual on/off lever transfers switch opera-tion without disturbing daily or weekly preset schedule. Heavy dutysynchronous motor suitable for operation between -40°F and +140°F.Switch slider bar assures positive switching. Heavy duty terminalsaccommodate up to AWG No.8 wire.
OPERATION“Off” Setting - de-energizes the entire zone control circuit, thus de-energizing all heating-cooling equipment in the zone. This setting canbe used for extended summer shutdowns, etc.“Automatic” Setting - allows the Day-Night Clock Panel to cyclethe control system according to the program clock dial tripper set-tings.To Set Trippers - Refer to picture for typical setup of a Seven DayProgram. Two trippers must be used for each day; an “A” tripper forswitching from “Night Setback” to “Day Operation” and a “B” trip-per for switching from “Day Operation” to “Night Setback”.
CAUTION: To set the correct day and time at beginning of initialstart-up, ROTATE THE PROGRAM CLOCK DIAL CLOCKWISEONLY. DO NOT ATTEMPT TO TURN POINTER!Adjusting and Maintenance of Time Switch:1. Periodically check trippers to insure that they are tightly fastened
to Program Clock dial. CAUTION: TIGHTEN TRIPPERS WITHFINGERS ONLY!
2. Rotate Program Clock dial CLOCKWISE one hour in Spring toadjust for daylight saving time (in areas where required). In Fall,carefully rotate clock dial CLOCKWISE approximately one fullturn to reset at correct day and time for standard time. Check alltrippers to insure they have not moved during rotation.
3. The Program Clock motor is permanently lubricated. Lubricationof other parts is not required.
4. The Program Clock switch contacts are factory set and need nofield adjustment.
4 PoleTMC71 311-057070-001 Seven Day 120 2 N.O. 40
2 N.C.
Renewal VoltsModel Part No. Operation 60 Hz Switch Amps